Verslag van de NMV-excursie naar de Rijnstrangen in natuurgebied Gelderse Poort, 17 september 2022

The Rijnstrangen are two former branches of the Rhine which were disconnected from that river in the sixties of the previous century. They are part of the 18,560 ha large Gelderse Poort nature area, one third of which has Natura 2000 status. On initiative of the Netherlands Malacological Society (NMV) on 17 September 2022 ten people, malacologists and their allies, explored the malacofauna of the Rijnstrangen at four locations. In all 64 mollusc species were encountered among which 20 species of land snails, 26 freshwater snails and 18 freshwater mussels. Only one land snail species and three of the freshwater species found appear on the Dutch Red list, among the latter the ‘threatened’ pil clam species Euglesa pseudosphaerium and the ramshorn snail Anisus vorticulus which enjoys protection through the EU Habitat Guideline. Remarkable was the absence of common freshwater invasive exotic species like the Asian gold clam Corbicula fluminea and Jenkins’ spire snail Potamopyrgus antipodarum from the examined sites.